Intermittent fasting is nothing new. Humans have fasted for most of their history, whether it’s during the typical overnight period, during more extended periods of food scarcity, or for religious reasons.
What is new is that clinical research on IF’s benefits for health and longevity is beginning to catch up.
Data show that IF, when done properly, might help extend life, regulate blood glucose, control blood lipids, manage body weight, gain (or maintain) lean mass, and more.
Rather than something we’re forced to endure – a result of poor food availability or cultural expectations – IF is becoming something that health and physique-oriented people are seeking out in order to keep their bodies in top shape.
The proposed benefits of IF in animals and humans read like a laundry list of “look better,” “feel better,” “live longer” physiological changes. These include:
blood lipids (including decreased triglycerides and LDL cholesterol)
blood pressure (perhaps through changes in sympathetic/parasympathetic activity)
markers of inflammation (including CRP<, IL-6, TNF, BDNF, and more)
oxidative stress (using markers of protein, lipid, and DNA damage)
risk of cancer (through a host of proposed mechanisms; we’ll save them for another review)
cellular turnover and repair (called autophagocytosis)
fat burning (increase in fatty acid oxidation later in the fast)
growth hormone release later in the fast (hormonally mediated)
metabolic rate later in the fast (stimulated by epinephrine and norepinephrine release)
appetite control (perhaps through changes in PPY and ghrelin)
blood sugar control (by lowering blood glucose and increasing insulin sensitivity)
cardiovascular function (by offering protection against ischemic injury to the heart)
effectiveness of chemotherapy (by allowing for higher doses more frequently)
neurogenesis and neuronal plasticity (by offering protection against neurotoxins)